diff --git a/index.html b/index.html
index 01ce1e24eb..ee2ca7ad4d 100644
--- a/index.html
+++ b/index.html
@@ -43,9 +43,7 @@ this repository contains the full copyright notices and license terms. -->
                 <div class="navbar-header">
                     <button type="button" class="navbar-toggle collapsed"
                         data-toggle="collapse" data-target="#main_navbar">
-                        <span class="icon-bar"></span>
-                        <span class="icon-bar"></span>
-                        <span class="icon-bar"></span>
+                        <span class="caret"></span>
                     </button>
                     <a class="navbar-brand" href="javascript:void()" data-toggle="offcanvas">
                         <span class="glyphicon glyphicon-menu-hamburger"></span>